Spray cleaning apparatus for caul screens

Abstract

A spray cleaning apparatus for cleaning the surface of a caul screen includes at least one cleaning head assembly having a cleaning head in fluid communication with a pressurized fluid source. The cleaning head has an upstream end and at least one outlet nozzle in fluid communication with the upstream end, and which are operable to direct a generally linear high pressure fluid stream onto the surface of the caul screen. The cleaning head assembly is moveably mounted on a support beam so as to be maintained a substantially fixed distance from the caul sheet. A conveyor reciprocally moves part of the sheet beneath the cleaning head assembly, with the cleaning head being indexed in movement along the support to successively reposition cleaning fluid flow relative to the sheet.

Description

SCOPE OF THE INVENTION[0001]The present invention relates to an apparatus for cleaning screens and other porous sheets, and more preferably a spray cleaning apparatus used to dislodge cellulose fibers, waxes, resins and other debris from wire mesh or caul screens used in fiberboard and oriented strand board manufacturing applications.BACKGROUND OF THE ART[0002]The use of caul screens in fibreboard, particleboard and oriented strand board (hereinafter collectively referred to as “(OSB)” manufacturing is well known. Caul screens are semi-rigid or flexible woven metal mesh screens having a pore size of 0.1 to 0.3 mm. The screens are used as a backing layer to convey heat activated resins together with wood fibers and other cellulose strands into a hot press. The press is then operable to compress and fuse the fibrous materials with the resins into a fiberboard / oriented strand board panel. Following formation, the panel is separated from the screen and trimmed. Any screens which thereaf...

AI Technical Summary

Benefits of technology

"The present invention provides an automated system for cleaning the surface of porous sheets, such as mesh screens or caul screens, by applying a high-pressure cleaning fluid to remove debris and resin from the sheet. The system includes a cleaning head assembly with multiple outlet nozzles that can be moved over the sheet to clean different areas. The cleaning head is mounted on a support beam and can be rotated to direct the cleaning fluid in a different direction. The system also includes a conveyor for moving the sheet in relation to the cleaning head, allowing for easier cleaning of the sheet. The cleaning fluid is preferably surfactant-free water, and the system can be used with different cleaning fluid compositions. The invention provides a more efficient and effective way to clean porous sheets, especially for industrial applications such as screen cleaning."

Problems solved by technology

Conventional manufacturing systems suffer the disadvantage in that the manual pressure washing of screens is both labour intensive and inefficient.

As a result, the pressure of the cleaning fluid stream as it leaves the nozzle is comparably low, often providing an output stream of water at pressures as low as of 250 psi or less.

The lower water pressures are often insufficient to effect penetrating of the cleaning fluid through smaller sized mesh apertures.

This problem is particularly acute where water alone is used as a cleaning fluid, and without the benefit of surface tension reducing surfactant additives.

As a result, while manual pressure washing may achieve partial cleaning of the face surfaces of a caul screen, it is frequently ineffective in dislodging resins and / or other debris from within the mesh openings themselves.

The discharge of excess water may disadvantageously result in conveyor belt or pulley slippage, or other unintentional wetting and / or lubrication of system components.

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